Pressure-regulation means



C. L. HOWSE PRES SURE REGULATION MEANS Dec. 11,1928.

Filed March 2. 1922 Patented Dec. 11, 1928.

UNITED STATES 1,694,507 PATENT OFFICE.

CURTIS L. HOWSE, OF DETROIT, MICHIGAN, ASSIGNOR TO A. W. CASH. COMPANY, A.

CORPORATION'OF DELAWARE.

PRESSURE-REGULATION MEANS.

Application filed March 2, 1922. Serial No. 540,649.

Regulation of pressure delivered from a steam boiler, for variation of the delivery pressure consistently with, (and often oppositely to) variation in boiler pressure, is often desirable. In the operation of forced-draft boilers, for example, and particularly a boiler equipped with an underfeed stoker, it is desirable so to regulate steam delivery to a fanengine that the fan may accommodate the air supply to steam-pressure conditions existing in the boiler, reducing the air supply as boilor pressure rises and increasing it as boiler pressure drops. This of course, tends automatically to maintain combustion at a rate stabilizing the boiler pressure; and to this end steam pressure in the engine-supplying main should be reduced consistently with rise of pressure in the boiler, and vice versa.

One of the objects of my present invention is to provide a simple, efficient and inexpensive apparatus served with steam from the boiler as its only fluid-pressure medium for regulating the steam-delivery consistently, or harmoniously, with the boiler-pressure-variations, and I have shown my invention as applied to fan-engine regulation wherein the delivery-pressure is varied op ositely to the variations of boiler-pressure. lore especially I provide for such regulation wholly by automatic valving mechanisms and appropriate connections, in which structures and com binat-ions more specific features of my invention reside.

In the drawings wherein I have shown a single embodiment of my invention for purposes of illustration, Fig. 1 is a diagrammatic elevation with parts broken away showing a steam boiler equipped with a stoker and with regulating mechanisms for the'fan-driving engine in accordance with my invention; Fig. 2 is an enlarged sectional view of the valving structures detached.

Referring to the particular installation illustratively shown, 10 represents a steam boiler equipped with an underfeed stoker 11 to which air is supplied from the blast fan 12 which is driven by a steam engine 13 to which the regulation is to be applied. A steam pipe 14, which I will term the main supplies the engine, preferably through a governed throttle valve 15, conventionally shown. In this pressure main the main regulat-ing valve 16 is connected, the valve proper thereof serving to control steam flow through the pressure main, and the automatic actuating elements of such regulating valve are influenced by variations 1n boiler-pressure.-

Specifically I employ also a secondary or auxiliary valve 17 serving as a pressure-regulating relief valve to control pressure conditions affecting the actuating mechanism of the main valve 16 and create substantial constancy of pressure in the main-valve area that it controls, notwithstanding that the fluid supplied to such area is of fluctuating pressure, such fluid being preferably steam from the boiler.

Details of the main valve structure may be varied, but in the casing 18 of the valve 16 the supply-port 19 between the upper inlet chamber and the lower outlet chamber is closable by a double-seat valve-proper 20 which opens upwardly. A restricted opening 22 through the head of chamber 21 admits boiler pressure from the main to the lower chamber or opening chamber 23 of diaphragmcasmg 24; the diaphragm 25 separating this chamber from the upper or closing chamber 26. The upper head of valve stem 27 bears against the underside of the diaphragm and is pressed upwardly by spring 28 tending to ra1se the diaphragm and open the valve. The spring 28 may be a light one, adapted to counteract only a small percentage of the boiler pressure which is to be exerted in closingchamber 26 above the diaphragm; and in aid of the spring, in valve-opening effort, a substantially constant pressure is to be maintamed 1n the opening chamber 23 as by, means of pressure-introduction through restricted port 22 and pressure-relief through the larger valved opening of an auxiliary relief valve 17 such pressure being of the same order as the boiler pressure (i. e., far above atmospheric pressure) but somewhat lower than the boiler pressure, so as to be below the expected low-limit of boiler-pressure fluctuation.

Specifically from a boiler-supply pressure source (preferably direct from the boiler itself) a steam-line 30 is led to the valve-closing diaphragm chamber 26, and from the valve opening diaphragm chamber 23 (which, it will be remembered, has restricted communication with the intake of valve 16 through port 22) a pipe 31 leads to the auxiliary valve 17. This valve 17 may be a standard pressure-relief valve with a diaphragm 32 forming one wall of the inlet chamber 33 into which pipe 31 opens, said diaphragm being loaded to close, as by a spring 34- adjustable as to tension by stem 35. The outlet pipe 37 may lead to any convenient lower pressure area; preferably to a point between the governor valve and the engine cylinder, so that the escaping steam may be used in the engine but so that the relief connection through pipe 37 is not subjected to high back pressure.

Thus, it will be seen, the main valve proper is controlled inposition by a pressure-movable part, as diaphragm 25, which is subjected to mechanical loading, as by spring 28, tending to move it in one direction and is also subjected to opposed fluid pressures derived from a fluctuating-pressure source. These opposed pressures are applied respectively through the chamber-structures 23 and 26 and their pressure-receptive connections, the one such pressure, opposing the mechanical load ing, being the substantially unmodified boiler-pressure, and the other such pressure, acting in the same direction as the mechanical load, being a suitably-proportioned, lower pressure derived from the fluctuating-pressure source, but modified to render it substantially constant. For the most convenient development of this constant lower pressure the initial steam pressure, diminished by admission through a restrict port to a chamber 23 relieved by an automatic pressure-regulating relief valve, is employed.

In operation, the main valving element 20 will normally float in partly open position, supplying steam to the fan engine through the port 19 and the engine-ward side of main 14, which is provided with throttle-valve 15. Boiler pressure acts directly on the top of the diaphragm 25 of the main valve 16 tending to close it, but this pressure is counterbalanced by, jointly, the lower pressure substantially constantly maintained in chamber 23 and the upward thrust of spring 28. While duct 22 tends to keep the chamber 23 under boiler pressure, the auxiliary valve 17 operates automatically to maintain the pressure in saidv chamber 23 practically constant, and lower than the boiler pressure; and by adjustment of screw 35 the relief-valve may be predetermined. Of course, any tendency of fluid pres sure in theconnected chambers 23 and 33 to rise above the desired amount is substantially counteracted by increased opening of the auxiliary valve, and tendency of such pressure to drop is met to closing movement of the auxiliary valve (the escape pipe 37 from which leads to some delivery point where the pressure is always lower than the pressure in the chamber 33). I

Thus it will be seen-that great sensitiveness of operation of the main valve is obtained since the position of the main valvingelement 20 is determined by the balancing of relatively light spring 28 against that small percentage of total boiler pressure which represents the preponderance of fluid pressure in ,a valve-positioning part, means for mechani- This regulation of delivery pressure by a valve governing the delivery pipe, with its position-controlling means acted upon in one direction by boiler pressure, and in the other direction by a'mechanical loading and a constant fluid pressure derived from the boiler but slightly lower than the boiler pressure, I believe to be broadly new.

While I have herein described in some detail a particular embodiment of my invention it will be seen that many changes in details in construction and arrangement may be made without departure from the spirit of my invention within the scope of the appended claims.

I claim:

1. The combination with a steam boiler, a steam engine to be regulated consistently with boiler pressure, and regulating means comprising a valve connected to control communication between said engine and boiler and valve-operating means, said operating means comprising a valve-moving part, means for imposing a relatively small mechanical load on said moving part, means adapted and arranged to modify fluctuating fluid pressure to substantial constancy and maintain a substantially uniform fluid pressure of the order of, but lower than, the boiler pressure, acting on said part in the same direction as the load, and connections for imposing boiler pressure on said part in opposition to said substantially constant pressure and mechanical load.

2. The combination with a steam boiler and a steam engine to be operated consistently with boiler pressure, of engine-regulating means comprising a valve proper controlling communication between the engine and boiler,

cally loading said valve-positioning part for movement in one direction, means adapted and arranged to modify fluctuating fluid pressure to substantial constancy and subject said valve-positioning part to substantially constant fluid pressure of the order of, but lower than, the boiler pressure, tending to move it in like direction, and means for subjecting the said part to boiler pressure for moving it in opposite direction.

3. The combination with a steam boiler and steam main, of means for regulating delivery through said main to decrease delivery as boiler pressure rises and increase it as said pressure drops, comprising a valve-proper controlling steam delivery through the main, a valve-positioning part, means for imposing a mechanical load on-said valve-positioning part tending to open the valve, means adapted and arranged to modify fluctuating fluid pressure to substantial constancy and impose a substantially constant pressure of the order of, but lower than, the boiler pressure, on said valve-positioning part to move it in like direction, and means for imposing boiler pressure upon said valve-positioning part tending to move it in opposite direction to close the valve.

4. The combination with a steam boiler and steam supply main, of means for varying the opening of said main consistently with variations in boiler pressure comprising a valveproper for the main, a valve-positioning part to govern its opening and closing movement, means imposing a mechanical load on said valve-positioning part to move it in one direction, means adapted and arranged to modify the fluctuating fluid pressure to substantial constancy and impose it as a substantially constant fluid pressure of the order of, but lower than, the boiler pressure, on said part for moving it in like direction, and means for imposing boiler pressure on said part tending to move it in opposite direction.

5. The combination with a steam boiler and steam supply main, of means for varyng the opening of said main consistently with variations in boiler pressure comprising a valve-proper for the main, a valve-positioning part to govern its opening and closing movement, a loading spring acting on said valve-positioning part tending to move it in one direction, means adapted and arranged to modify the fluctuating fluid pressure to substantial constancy and impose it as a substantially constant fluid pressure of the order of, but lower than, the boiler pressure, on said part for moving it in like direction, and means for imposing boiler pressure on said part tendng to move it in opposite direction.

6. The combination with a steam boiler and steam main, of means for controlling the opening of said main consistently with variations in boiler pressure, comprising a valve proper for the main, a diaphragm controlling the position of said valve proper, a spring acting upon said diaphragm in one direction, means for supplying boiler pressure to act on said diaphragm in opposition to said spring, and means adapted and arranged to modify the fluctuating boiler pressure to substantial constancy and impose it as substantially constant pressure of the order of, but lower than, the boiler pressure, to act on said diaphragm in like direction with said spring.

7. The combination with asteam boiler; and steam main, of means for controllingthe opening of said main consistently with variations in boiler pressure, comprising a valve proper for the main a diaphragm controlling the position of said valve proper, a spring acting upon said diaphragm in one direction, means for supplying boiler pressure to act on said diaphragm in opposition to said spring, and means for supplying substantially constant pressure to act on said diaphragm in like direction with said spring, said means including a premure chamber having restricted communication with the source of steam supply and a pressure-regulatin relief valve communicating with said cham er.

8. The combination with a steam boiler and steam main, of means for regulating the opening of said main consistently with, va-

riations in boiler pressure, comprising a valve proper for the main, a diaphragm controlling the position of said valve proper, a spring acting upon said diaphragm in one direction, means for supplying boiler pressure to. act on said diaphragm in opposition to said spring, and means for supplying substantially constant pressure to act on said diaphragm in like direction with said spring, said means including a pressure chamber having restricted communication with the source of steam supply and a pressure-regulating, automatic, relief valve communicating with said chamber, and having provision for adjustment of its relief-pressure setting.

9. In a system of the characer described, the combination with a steam boiler, a draft fan therefor, a steam engine for operaitng said fan and a steam main connecting said fan and boiler, ofengine regulating means comprising a valve proper controlling the main, a diaphragm controlling valve positions, pressure chambers above and below said diaphragm, a spring in said lower chamher acting on said diaphragm to cause valve opening, a connection between said upper chamber and the source of boiler pressure supply, and a pressure-regulating, automatic, relief valve communicating with said springchamber, said spring chamber having restrictedcommunication with a source of boiler-pressure supply, whereby the boiler pressure imposed on one side of the diaphragm may be balanced by a predetermined lower' pressure and the spring.

10. In a system of the character described, the combination with a steam boiler, a draft fan therefor, a steam engine for operating said fan, a steam main from said boiler to said fan including a throttle valve operatable normally to maintain relatively low pressure in its side toward the engine under demands of the running engine, of means for regulating the steam supply to said engine comprising a valve-proper for the main, a valve-positioning diaphragm, a spring acting to open iio the valve, .pressure chambers on opposite sides of said diaphragm, one said chamber having connection with the steam boiler for exertion of pressure to close the valve, the

: other said chamber having restricted communication with a point subjected to boiler pressure, and a relief-valve structure having an inlet connected to the second-mentloned chamber of the main valve and having an outlet connected to the engine-side of the 10 throttle valve, said relief-valve structure said valve-proper, and means imposing a 15 closing-load thereon.

CURTIS L. oWsE; 

